Impurity band conduction (IBC) infrared (IR) detectors such as blocked impurity band (BIB) detectors and solid state photomultipliers (SSPMs) are known in the art and described in U.S. Pat. No. 4,568,960 entitled "Blocked Impurity Band Detectors"; U.S. Pat. No. 4,586,068 entitled "Solid State Photomultiplier"; U.S. Pat. No. 4,586,074 entitled "Impurity Band Conduction Semiconductor Devices"; and U.S. Pat. No. 4,757,210 entitled "Edge Illuminated Detectors for Determination of Spectral Content". These prior patents provide background information for the present invention, and their teachings are incorporated herein by reference.
The current generation of IBC infrared detection devices has less than desired efficiency in detecting photons in the short wavelength infrared (SWIR) spectrum Although the quantum efficiency of IBC devices in the SWIR region can be improved greatly by edge illumination, this approach is difficult to implement in multiplexed arrays or large area discrete detectors. Thus, there is a need for an IBC device with improved quantum efficiency in the SWIR region that is suitable for front-illuminated detectors and for large area back-illuminated arrays having arbitrary pixel dimensions.